Accumulation and transport of cadmium and lead in the seedlings of maize

After treated with different doses of Cd(2+) and Pb(2+), the contents of the metals in the roots and leaves of maize(Zea mays L.)were determined by the scanning microscopy-X ray microanalysis and the atomic absorption spectrophotometer. The results showed that there was more Cd accumulated in the seedlings of maize than Pb. The Pb contents in the cortex was more than that in the stele and in the xylem parenchyma was more than that in the vessel while Cd contents in these parts appeared to be another way around, indicating that Pb was transported mainly in the apoplast and Cd in the symplast